Bessa R3a "center"weight

[galaxenspreside]

I have understood that the Bessa R3a has an off-center weighted meetering.

In order to take light reading accurately I believe it is importent to understand the meetering system, especially when shooting slide film.

Does anyone now where I can find information on the weight pattern, preferably a plot on the weight as a function of image coordinates or similar.

Thanks,
Richard

 

[f/stopblues]

This may be of help: http://www.cameraquest.com/voigtbmeter.htm

 

[galaxenspreside]

Thanks,
Lower left, a third from the bottom and a third from the left is where the maximum of the weight function is, it seems.

I get the impression that more specific information on weight pattern simply isn't available, but this is better than nothing.

Thanks again
/Richard

 

[pau3]

However, you can probably test it easily. Just point to some white
spot in a black surface and look at the metering as you move
the white spot in the viewfinder. I did in my R2, and although
I may be wrong, I noticed that the peak is at one third of
the bottom, but in the central vertical line of the viewfinder.

 

[ronnie_retro]

I think that's about all there is to the weighting. The inside surface of the shutter is a uniform light color, and the photodiode should have a circular (symmetric) field of view from where it is aimed on the shutter.

Regards

 

[wyk_penguin]

But it is not aimed at the middle of the curtain!!!!